In checking the 1840 Adams Co, IL census I found no Packard's however, I did find one in Hancock Co, IL which borders Adams Co.By 1840, Matilda Jane would have been about 15-16 yrs old IF 1824 is her correct birth year. Noah Packard has one daughter age 10-under 15 b. 1826-1830 in his household.He may be the same Noah Packard that was in Geauga Co, OH and appears to be your most likely prospect.

The only other Packards that I found in IL in 1840 were Robert Packard in DuPage Co (1 female 20-under 30) & Philip Packard in Pike Co IL who had no young females in his home, however, Pike Co is also a border county to Adams Co.

Since Adams Co is bordered by two MO counties (Marion & Lewis Co's) I checked MO and only found some in Van Buren Co (no longer exists) which was across the state & was on the western border of MO